Dominique Strauss-Kahn has filed a $1million lawsuit against the maid who accused him of sexual assault.

The disgraced ex-IMF chief was arrested a year ago when Nafissatou Diallo accused him of trying to rape her in his luxury suite at the Sofitel Hotel in New York.

Prosecutors later dropped all charges after Diallo’s ­credibility was questioned.

She nonetheless sued the Frenchman but in the countersuit, he accuses her of “knowingly and intentionally making a false report to law enforcement authorities”.

A judge this month knocked back Mr Strauss-Kahn's claim that he had diplomatic immunity.

Ms Diallo's lawyers called the counter-suit a "desperate ploy."

Ms Diallo, now 33, says Mr Strauss-Kahn, 63, chased her down, tried to yank down her tights and forced her to perform oral sex.

He was arrested, resigned from the IMF and spent several days behind bars and three months on house arrest before prosecutors dropped the criminal case, saying Ms Diallo had lied about her background and changed her account of what she did after leaving the hotel room.

Ms Diallo's lawyers called Strauss-Kahn's defamation claim an example of the "misogynistic attitude" of a man who now faces preliminary charges of being involved in a hotel prostitution ring in France.

As of last week, French investigators also were studying accusations that Mr Strauss-Kahn may have been involved in a rape during a sex party in a Washington hotel in 2010.

Separately, a French writer accused him last year of having tried to rape her during a 2003 interview, an accusation prosecutors said was too old to try.